Advice on MMA test results for me and... - Pernicious Anaemi...

Pernicious Anaemia Society

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Advice on MMA test results for me and Jo5454 please

CherylclaireForum Support

Can anyone help us with the following questions:

What does it mean exactly if your MMA is raised?

What, above 280 nmol, is considered "very high" ?

What other conditions, aside from B12 deficiency, might be construed from raised levels?

Is it unusual for MMA to still be raised after starting 3-month B12 injection programme?

Is it unusual to be tested at this stage?

Should this be an NHS test?

Thanks in advance.

11 Replies

Reference ranges vary depending on the assay used. 280 nmol/L is within range for some assays, so it's not going to be classified as 'very high'.

High levels of serum MMA can also be indicative of kidney problems.

CherylclaireForum Support in reply to fbirder

Thanks fbirder,

I've had a lot of routine blood tests. Are kidney problems usually identified from these/ not?

351nmol after B12 injections started, seems unusually high, although I have no idea what my previous level was.

You don't give ranges for MMA but 280 is usually top of the range and would, of course, be very high.

Although there is no reliable test, MMA is considered more reliable and a high result with, for instance, low serum B12, plus symptoms, would indicate B12 deficiency.

The latest research document gives information on MMA on page 3 and again under 'How is response to treatment assessed' - bottom of page 4 :

You will also see from the above that MMA levels should fall after treatment with B12 injections, which would help indicate a correct diagnosis.

I'm not sure if it answers all your questions but hope it helps....

CherylclaireForum Support in reply to Polaris

Thanks Polaris,

Reason I asked was that after 2nd 3-month injection of B12, nothing seemed to happen and I was getting gradually worse again- 6 weeks later, was serum MMA tested : 351nmol. Now I'm having reloading. Getting better, but brain not there yet.

Polaris in reply to Cherylclaire

Hi Cherylclaire

It looks like the second MMA test showing a higher result was effective in enabling you to have more loading injections, contrary to the BMJ document, which suggests, wrong diagnosis if MMA doesn't fall 🤔. Looking at your past posts though, I notice that you've had dental treatment fairly recently and I'm wondering whether the analgesics used could have affected your B12 uptake ?

Good news that you're having loading injections, as it would seem that, like so many others, an injection every three months is not enough and it is so important for your brain that you have sufficient B12 early on in treatment.

"The need for quick and correct treatment is emphasised further by the fact that after a year of treatment only 4 % of patients are fully recovered. Fortunately half of the patients have experienced a lot of improvement in their symptoms after a year of treatment but there are still a lot of patients with remaining symptoms, who could possibly have recovered if their treatment was started promptly and adequately."

I hope you begin to feel much better soon.

CherylclaireForum Support in reply to Polaris

Hi Polaris-

Read the BMJ document: as usual, good in parts, disappointing in others.

Particularly dislike misinterpretation of the loading for those presenting with neuro symptoms being stopped at 3 weeks- wasn't this merely suggested as a review point in the haematologists' guidelines? No-one gets loading doses every other day anyway: since surgeries are closed at weekends, this would surely involve self-injection....and then where would we be ????

DID like that there was emphasis on rapid response, and symptoms prioritised over test results. PASoc listed at back too.

As for MMA reading being high AFTER injections started- this was the first MMA test result, so now impossible to know what initial reading might have been although I know it should not be high at all. You are right: I did have a tooth out and then got bone infection. Did tell dentist about B12 and she said she understood and put it on my record, so hoping no ill effects there.

Wrong diagnosis always possible but difficult to imagine what other illness would cause all these random symptoms. St Thomas' gastroenterology appointment next week might give definitive answer, and finally someone might say Pernicious Anaemia to me!


very high for MMA is going to in the region of 2x+ what it should normally be (my guess).

after being on B12 injections it's unlikely that MMA is going to be useful. Its a test that really needs to be done before you start treatment. It may sometimes identify a functional B12 deficiency after treatment has started but I'm not sure that this is always the case - but can be useful when it does.

To be honest it would be far more useful if professionals working in the NHS were a lot more aware of how B12 works and what lack of it does to people, and the limitations of the serum B12 test. It is, I think, quite an expensive test so I don't think it would be cost effective for it to be routine - but it would be very cost effective for medics to be aware that symptoms are important when evaluating B12, what those symptoms are, that it isn't a dangerous treatment at all ... and that it isn't an expensive treatment. Trialling B12 would cost a lot less.

And as fbirder says, levels can also be raised by kidney problems


High MMA serum values are also found in people with renal insufficiency, hypovolemia (decreased volume of circulating blood) and intestinal bacterial overgrowth. In these cases MMA levels cannot be used to diagnose B12 deficiency though a B12 deficiency might simultaneously exist. In the case of kidney disease ( or hypovolemia) MMA levels in urine can be tested.

fbirder in reply to PAS-admin

Unfortunately uMMA isn't available on the NHS. So us Brits have to have the serum test and assume that high MMA combined with low B12 is a sign of deficiency. High MMA and high B12 would require further investigation - kidney function being the main one.

PAS-adminAdministrator in reply to fbirder

Raised MMA is usually B12def. Creatinine is usally included in standard bloodwork anyway. But it's easy to test. High MMA, take B12, re-test MMA. Significant drop = proof B12def. No change, investigate further.

CherylclaireForum Support in reply to PAS-admin

As, 6 weeks after my 2nd 3-month injection, my MMA level was 351, I'm being reloaded and given ferritin and folic acid (both of which on low side but within normal range) . My injections after loading will be more frequent. I guess at some point, blood test will be taken again to check MMA reduced (?)

The nurse keeps asking about my "poor arms" but my one concern currently is my poor brain....besides which, I never feel the injections and don't get sore arms. Lucky that way.

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